Return-duct connection for



May 20, 1941. J. J. HoLUB RETURN-DUCT CONNECTION FOR FURNACES Filed Jan. 17, 1940 Patented May 20, 1941 Paar ortie RETURN-poor coNNEcTroN Foa" FURNAcEs 2 Claims.

'I'his invention pertains to an improved structure for connecting a cold-air or return duct to the shell of a warm-air furnace. More particularly the invention relates to the details of a shoe that is of a knock-down construction which permits a number of the articles in disassembled form to be enclosed in a relatively small packing case for storage or shipment.

The several sections of the article are provided with self-locking and interlocking elements which permit the article to be completely assemble-d by the workman at the time the shoe is being installed on the furnace, and this assembly may be performed practically without the use of tools or special devices. The particular construction of this no-vel device is such that after it has been assembled and installed it is self-sustaining,

At one end this device is preferably of rectangular cross-section, while at its other end the device is of cylindrical cross-section, and there is an intermediate portion -that merges at its ends into the respective rectangularl and cylindrical portions. The axes of the end portions are at substantially right-angles to each other,

while the merging intermediate portion has its axis oblique to the axes of said respective end portions.

In order to provide a knock-down construction, the cylindrical end portion or collar is made of a single piece of sheet-metal having releasable interlocking elements at the proximate edges of the sheet to maintain said end portion in cylindrical form, and there is an annular beaded ange along an obliquely formed lower margin for locking engagement with the adjacent margin of the inclined portion of the shoe body. The body of the structure composes the rectangular end portion and the upwardly extended intermediate portion that are preferably combined into one composite unit which is made up from upper and lower sections of sheet metal. The proximate margins of these two sections which are substantially parallel to each other, are provided with novel interlocking means to permit quick assembly or disassembly of the respective sections. After the several parts of this device have been assembled with each other, and the end portions thereof tted to the furnace shell and to the cold-air return-pipe, the structure is effectively maintained against accidental separation or dislodgement. On the other hand, the structure may be readily disassembled and knocked-down should occasion require it.

One of the principal aims of my invention is to. provide an article ofthe kind described that is novel in the construction and arrangement of its parts and is dependable in the performance of its functions. It is also an aim of my invention to provide a structure which is made of sturdy-parts of relatively simple formation and capable of withstanding severe usage. Another advantage is that the article is economical to manufacture so that it may be sold to the user for a reasonable retail price.

Objects and advantages, other than those mentioned will of course be obvious to persons skilled in the art after my invention is understood from the following description. I prefer to accomplish the numerous objects of my invention and to practice the same by means of the structure hereinafter set forth and as more particularly pointed out in the appended claims, reference being herein made to the accompanying drawing that forms a part of this specification.

In the drawing:

Figure 1 is a view in perspective showing my invention in assembled form.

Figure 2 is a transverse section on line 2-2 of Figure 1 drawn in perspective and enlarged.

Figure 3 is an enlarged vertical section on line 3 3 of Figure 1.

Figure 4 is a perspective of the structure shown in Figure 3 and illustrating in detail the manner of assembling the side wall and bottom wall of the rectangular portion of the device.

Figure 5 is an enlarged horizontal section on line 5-5 of Figure 1 showing details of the collar seam.

Figure 6 is a perspective of the structure shown in Figure 5 and illustrating in detail the manner of assembling the proximate ends of the sheet forming the collar.

Figure '7 is an enlarged section on line 1--1 of Figure 1 showing details of the oblique seam.

Figure 8 is a View in elevation of the parts shown in Figure 7.

It is understood that the drawing is schematic and is for the purpose of illustrating a typical or preferred embodiment of my invention. In'said drawing the same reference characters are used to identify the same parts wherever such parts.

appear in the different views.

The circular outer end portion of the structure, which has its axis vertical, I have herein designated as the collar for the purpose of convenience, and for the same reason the remaining portion of the structure, which includes the rectangular part and the oblique merging part, I have designated as the body.

This body preferably comprises. upper and lower sections each of which includes members of the rectangular part and the oblique merging part. In the upper body section the rectangular part is designated as A and the oblique part is designated as B in the drawing, and these two parts are formed from a single piece of sheet metal. In the lower section the rectangular part which cooperates with the upper part A has been designated as A', while the oblique part which cooperates -with the upper part B has been designated as B', and these parts are likewise formed from a single piece of sheet metal.

The part A embodies spaced vertical side walls 5 and a horizontal top wall 6 that is disposed substantially at a right angle to and is connected to the top edges of said vertical wallsl thus forming a member having a rectangular crosssection. The end of this member that is remote to the oblique portion is adapted for connection to the shell of the furnace in any suitable manner. 'Ihe part B of the upper section, which is integral with the part A just described, has an upwardly inclined lower margin that extends up to about the plane of top wall 6 and has its upper wall 1 correspondingly inclined upward from. the adjacent margin of said top wall 6. Ihe sides and top of the part B are shaped so that they merge from a rectangular form at their inner ends into a continuous semi-circular or semi-cylindrical form at their outer ends. 'I'he transverse edge or upper margin of the part B is provided with an outwardly disposed concavofconvex bead 8 that assists in connecting the body to the collar as will later be described.

The lower part A' is a rectangular plate forming the bottom wall 9 of the adjacent portion of the body, and its longitudinal margins are provided with upstanding iianges IU that interlock with elements at the lower edges of the body side-walls 5. The metal forming side-walls 5 is bent into an inwardly disposed S-shape as shown in Figures 3 and 4 to provide an in-turned and upwardly extending ange I I and a downwardly disposed extension I2, and at the lower margin of this extension there is an up-turned lip I3 that is disposed in the seat or channel I4 formed by the lateral spacing of the flangeA and extension I2. This seat I4 is adapted to receive the marginal flange I of the bottom wall. For the purpose of locking these parts in assembly, suitable rigid lu-gs or bosses I5 are formed in the entering ange IIJ, which lugs or bosses are readily made by cutting short longitudinall slits I6 near the bottom of the flange and then oisetting the metal above the slits as shown in Figures 3 and 4 in order to provide shoulders at the lug margins of the slits I6 to engage the upper edges of the lips I3 when the flange I0 has been forced into the channel or seat between the flange I I and extension I2 as shown in Figure 3. These interlocked portions may be readily disengaged by moving the parts A and A in opposite longitudinal directions with respect to each other.

There is an oblique seam which detachably joins the inclined adjacent margins of the upper and lower body parts B and B. The margin of the metal sheet forming the upper body section B is provided along its oblique portion with an oi-set bend |'I and a short distance beyond this off-set has a reversely bent inwardly disposed ange I8 extending back to near the ofi-set where the metal sheet is given a second reverse bend to provide an extension I9. These bends provide an S-shaped formation along the margin of upper body par-t B into which the adjacent oblique margin of the lower body B' is adapted to be inserted, and, as shown in Figure 7, the outer edge of the ange extension I9 projects beyond the rst reverse bend that has been made to provide the inturned ange |8. Novel means are employed to draw the parts firmly together and maintain the body in assembly. This means comprises bolts 20 and nuts 2| that are disposed with the shank of the bolt passed through a hole in the lateral portion of an L-shaped bracket 22 secured to the body of part B and the nut is seated within the lateral portion of a J-shaped bracket 23 secured to the other body part B. 'Ihe lateral portion of J-shaped bracket 23 provides means to prevent rotation of the nut 2|, and in order to facilitate assembly of the bolt and nut therewith (prior to tightening the latter) the lateral portion of said bracket 23 is provided with an open longitudinal slot 24 as shown in detail in Figures '7 and 8 so that the bolt with the nut thereon may be quickly assembled with the bracket 23 without removing the nut from its bolt.

The collar C, which connects the body to the conduit or conductor pipe D, is preferably one piece of sheet metal of cylindrical shape with its axis substantially vertical and at a right-angle to the axis of the rectangular portion of the body. The upper edge of said collar is in a horizontal plane at a right-angle to the collar axis and its lower'edge, which joins the adjacent circular margin of the merging section B-B' of the body, in a plane is oblique to said upper edge and is also inclined with respect to the collar axis. For the purpose of identication the proximate marginal portions of the cylindrical metal sheet are designated as X and Y respectively as shown in detail in Figures 5 and 6.

The proximate edge portion Y is a straightedge 25 extending substantially the length of said proximate edge and there is a notched portion 26 made in the edge near the upper end thereof. Beyond the notch the metal sheet is given a reverse bend to provide an elongated outwardly disposed tongue 21 extending to the end of the edge Y. 'I'he other proximate edge portion X is provided with an oiset 28 extending longitudinally thereof from end to endl At its outer portion this margin is given a reverse bend to provide a longitudinal inturned flange 29 alongside the offset portion and near said oiiset bend the metal sheet is given a second reverse bend to provide stops or abutments 3| as shown in Figure 6. The tongue 2l of the edge Y is inserted into the seat 32 that is formed between the offset flange 29 and the body of the sheet, and thereafter the straight edge 25 is inserted into the seat or space between the flange 29 and the extension 3D. The respective portions X and Y are then moved relative to each other to engage the end of tongue 21 with the stop or abutment 3|.

The lower margin of the collar is provided with a bead 33 of concavo-convex form that terminates in an upwardly iiared flange 34 that is inserted into the inner concave portion of the bead 8, hereinbefore described, so that when the two sections B-B of the body are drawn together by the bolts 28 the bead 8 will clamp the flange 34 and maintain the collar assembled with the body. In order to prevent relative movement of the proximate portions X and Y of the collar in a circumferential direction which would have a tendency to reduce the diameter of the latter, the return pipe or duct D is inserted inside the collar as shown in Figure 1. When thus assembled the parts are prevented from accidental or unintentional disengagement.

From the foregoing it will be obvious the article which I have invented is of a completely knockdown character so that the three respective parts may be arranged in nested relation and placed in a relatively small carton` for shipment. In fact, several of these devices, each knocked-down and nested, may be stored and shipped in a relatively small package or carton, thus saving considerable space. The several parts or sections of a single article are adapted to be readily assembled at the place of installation without the use of special tools.

What is claimed is:

l. A knock-down furnace shoe comprising two metal sheets bent into hollow form to provide two meeting edges forming a seam and two walls extending away from the seam at substantially right-angles to each other; the meeting edge of one of said sheets turned inwardly and formed into an S-shape bend providing an elongated pocket the mouth of which is spaced inward with respect to the outer face of the sheet, and an inturned tongue along the free inner edge of the bend between the walls of said pocket, the walls of the pocket and said tongue lying wholly within the confines of the walls of the shoe; the meeting edge of the second sheet provided with a lateral flange which enters the pocket at the margin of the rst sheet, whereby said flange and the aforesaid S-shape portion are disposed within the angle formed by the two sheets whereby the outer surfaces of the walls are smooth and unbroken, and embossments on said ange adapted to abut the inner edge of said in-turned tongue.

2. A knock-down furnace shoe comprising two metal sheets bent into hollow form to provide two meeting edges forming a seam and two walls extending away from the seam at substantially right-angles to each other; the meeting edge of one of said sheets turned inwardly and formed into an S-shape bend providing an elongated pocket the mouth of which is spaced inward with respect to the outer face of the sheet, and an inturned tongue along the free inner edge of the bend between the walls of said pocket, the walls of the pocket and said tongue lying wholly within the connes of the walls of the shoe; the meeting edge of the second sheet provided with a lateral flange which enters thepocket at the margin of the rst sheet, whereby said ange and the aforesaid S-shape portion are disposed within the angle formed by the two sheets whereby the outer surfaces of the walls are smooth and unbroken, embossments on said flange adapted to abut the inner edge of said inturned tongue, and lateral strengthening walls along the edges of said embossments constituting reinforcing means between the walls of said pockets whereby to prevent transverse collapse thereof.

J OHN J. HOLUB. 

